This invention relates to apparatus for simulating the playing of a game of golf.
Numerous arrangements have been proposed for providing indoor facilities by which the playing of an 18-hole, outdoor game of golf can be simulated. Such arrangements are considered desirable for a variety of reasons including alleviating the overcrowding of existing outdoor golf facilities, and enabling year-round play in climates where year-round play at outdoor facilities is not possible. Additionally, the use of indoor facilities would typically be less strenuous and less expensive than would the use of outdoor facilities, and would enhance golf instruction and teaching capabilities.
The arrangements thus far proposed typically include a tee area from which a player may drive a ball and a target screen for receiving the ball and upon which is projected scenes of an actual golf course as viewed from successive locations of the lie of a golf ball looking toward the greens. Various sensing systems are utilized to determine the initial trajectory and speed of the ball, which information is then used to compute an estimate of how far the ball would have traveled had it not struck the target screen. The sensing systems generally employ, either singularly or in combination, photo-electric devices, acoustic pick-up devices or impact-detection devices for determining the path of a driven golf ball. Most often, two sensing devices are used, a first of which detects when the ball leaves a tee point or passes a plane near the tee point, and a second of which is spaced along the line of flight of the ball at a location to detect passage of the ball through that location. The time between detection by the first sensing device and the second sensing device, of course, can be used to ascertain the initial speed of the ball. Additionally, depending upon the nature of the sensing devices, information such as the azimuth and trajectory angle of the ball (with respect to elevation) may be determinable and thereafter used by computing apparatus to compute an estimate of how far the ball would have traveled and the location at which the ball would have come to rest had it not struck the target screen. These estimates are then used to ascertain which scene should be projected on the target screen, with the scene chosen reflecting the estimated lie of the golf ball with respect to the green.
Some exemplary prior art arrangements are disclosed in U.S. Pat. Nos. 3,591,184, 3,778,064, 3,655,202, 3,671,724, 3,712,624 and 3,759,528.
One of the main drawbacks of prior art arrangements has been the costliness of providing apparatus suitable for making calculations of the travel of a golf ball while taking into account such factors as spin of the ball. A drawback of arrangements which have used optical sensing systems has been the distraction that visible light (used with such systems) causes some players. Further, there is a problem with optical sensing systems "falsely" sensing the presence of a ball when no ball has been hit from the tee area. This may be caused, for example, by light being reflected from some foreign object which enters the area between the tee and the target screen. Such false sensing is undesirable since it might result in erroneous computation of the estimated distance of travel of the ball and a premature change of scene projected on the screen.